Inverter, MPPT (maximum power point tracking) control device for inverter and MPPT control method for inverter

The invention provides an MPPT (maximum power point tracking) control method for an inverter. The method includes the steps of acquiring current and voltage signals on the direct-current side and current and voltage signals on the alternating-current side, calculating direct-current power and alternating-current power according to the signals, judging whether or not the direct-current power and the alternating-current power satisfy a first preset condition, judging MPPT power direction change through the alternating-current power if yes, and judging MPPT power direction change through the direct-current power if not. The MPPT control method has the advantages that by means of detecting the direct-current power and the alternating-current power, when a sensor or a sampling circuit on one input side fails, MPPT power direction change is judged by the power on the other side, so that MPPT redundancy control is achieved, and problems of algorithm invalidation, energy loss and electricity generation device halt caused by the fact that the sensor or the sampling circuit on the input side fails in the prior art are solved.